No audio from 17" Powerbook except for startup chime

The sound on my 17" G4 Powerbook does not seem to be working any longer. I know there are some similar threads but I think my problem is slightly different because I get sound on startup (the startup chime) then when Leopard loads it seems to be dead.

When I press the volume keys (F4/F5) I see the volume indicator increase/decrease but I do not hear an alert sound.

When I go into System Preferences/Sound, "Internal Speakers" is grayed out under "Sound effects" but "Internal Speakers" shows up under the Output tab.

When I plug in headphones, I get no sound.

I've tried resetting the PRAM and open firmware.

I've tried creating a new user and the new user also has no sound.

I've tried repairing permissions, running disk warrior while booted from another drive, and a disk repair in disk utility, as well as fsck-fy and also clearing the cache files with applejack.

I am runnign Leopard on this machine, version 10.5.6.

I though it was a fried/disconnected sound card or a logic board issue until I realized that the startup chime was playing just fine.

Also, whenever I press the volume keys, I get the following error in system.log

Although by now, i do hope you found a solution.
I was almost ready to totally reinstall my OS when I found this little gem:http://forums.macosxhints.com/archive/index.php/t-32876.html
(pay special attention to the last post that states: Simply remove 'AppleDallasDriver.kext' from '/System/Library/Extensions/' that way you will only get error entry in the log and your sound will work fine)

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